The invention relates to a sleeve catheter for the wetting and infiltration of a vessel wall with a fluid particularly, medicine, preferably during routine treatment with a balloon catheter.
For the treatment of constricted passages in arteries, balloon dilation is recognized as an only little invasive but very effective and elegant method. Experience however shows that this treatment method has a high recurrence rate in the order of about 30% of the treated patients, that is, within a period of several months, for example, between 3 and 6 months, passage constriction will reoccur. It has been shown that this is at least partly caused by cell growth which is caused by the balloon dilation, that is, by expansion and rupture of the tissue. It is therefore desirable to provide the vessel area which is subjected to such balloon dilation additional treatment which counteracts such tissue growth.
Various methods for growth-inhibiting treatment are known, particularly, the application of energy, for example, by means of a laser or the localized treatment with special medicine. As carrier for the localized treatment with medicine it is known to use wire wall supports (so-called stents) whose use however is complicated and which cannot be removed.
It has also been proposed to use balloon catheters with perforated balloons so that, during the dilation procedure, medication can be administered for penetration into the tissue. However, this proposal was found to be unsuitable since already at the beginning of, and during, balloon expansion, uncontrollable amounts of medicine are lost so that it becomes impossible to apply a defined amount of medicine to the tissue wall areas to be treated for wetting of the tissue and infiltration into the tissue wall. During inflation of the balloon, that is, before the balloon wall abuts the vessel wall, a substantial amount of the medicine is released and this prematurely released amount of medicine does not reach the vessel layers to be treated and, consequently, an undesirably high dosage is required if the particular vessel area to be treated is to be exposed to a sufficient amount of medicine. Another disadvantage is seen in the fact that only an insufficient amount of pressure can be generated with a perforated balloon which may not be enough to expand the restricted vessel area.
It is desirable to overcome the disadvantages as described in connection with a perforated balloon, wherein however the effectiveness and the elegance of balloon dilation should be maintained and medication treatment of the tissue and the vessel wall should be facilitated during the same procedure without essential additional time input. It is therefore the object of the invention to improve the established balloon catheter procedure such that, on one hand, the high recurrence rate can be reduced by the simultaneous administration of medicine, and, on the other hand, the medicine is administered in the desired dosage and is applied essentially only to the tissue areas to be treated.